const markedStartupMilestones = new Set<string>(); /** * Records startup timing without coupling it to tracing, which is configured * only after authentication. */export function markStartupMilestone(name: string): void {  if (markedStartupMilestones.has(name) || typeof performance === "undefined") {    return;  }  markedStartupMilestones.add(name);  performance.mark(name);}